True: There’s not much maritime music that can actually be traced to the shores of the Chesapeake Bay, compared with, say, the wealth of whaling tunes. But a few years back, music historian John Townley dug up a roster of ditties that reflect the importance of the burgeoning Chesapeake shipping industry, and he and the Press Gang recorded them on “A Chesapeake Sailor’s Companion.” From songs about the tobacco trade to the more recent “Sailing Down the Chesapeake Bay” (a paean to Bay steamboats), Townley’s research takes us on a musical history tour inspired by, if not actually engendered by, the unique maritime attributes of the Bay. Long out of circulation, a CD of Townley’s classic recording has just been reissued by Adelphi/Genes Records of Silver Spring, Md. Ask for it at a record store near you (suggested list price: $15.95), or order it from the web: www.adelphirecords.com.